The invention will be described hereinafter on the basis of the example of a method for preparing tissue for use as a sealing means for a heart valve prosthesis. Although the present invention is particularly suitable for the preparation of tissue of this type, it is not limited to this application.
Methods for preparing biological tissue are known for example from EP 2 832 379 A1 and US 2001/004715 A1.
There are in principle two different types of heart valve prosthesis: mechanical valves, which are produced artificially, usually from graphite coated with pyrolytic carbon; and biological prostheses, often made of pericardium tissue usually originating from animal sources (for example pig or cattle). The heart valve formed from the biological or pericardial tissue is usually secured in a main body (for example a firm plastic framework or a self-expanding stent), and this is implanted at the position of the natural valve. Such heart valve prostheses can be, in particular, what are known as TAVI heart valve prostheses (TAVI stands for transcatheter aortic valve implantation).
A problem with prostheses of this type, in principle, resides in paravalvular leaks, that is to say blood which flows past between the surrounding vascular wall and the outside of the implant.